A third underground lake came to light in the Attica region after a group of online researchers and explorers discovered the body of water forming at the Kifissos River which flows through Athens reaching the Saronic Gulf at the southern boundary of the city.
The discovery by the group called “Geomythiki” was made at the end of 2024 and marks the third such revelation of a subterranean lake in the wider Athens region. The first lake was pinpointed in January 2021 at a footbridge in Perissos, situated in the municipality of Nea Ionia in the regional unit of North Athens.
Six months later, a second underground lake was brought to light in July 2023, near Athinon Evenues. Later, on December 31, 2024, the team uncovered a third, significantly larger underground lake near the Vehicle Technical Inspection Centre (KTEO) in Peristeri, a suburban municipality in the western part of the Athens agglomeration.
These lakes are the result of fractures in the riverbed of the Kifisos River, which have caused the formation of these water bodies. Remarkably, fish have been observed living in these lakes, as showcased in a video shared by the research team on their channel.
According to the members of the Geomythiki speleology team, the issue of stability is very concerning, warning the water needed to be drained so that engineers could assess the damage. “The underground lake in this third lake is in the worst condition we’ve ever seen.”
